ComparisonUpdated 2026-07-08 · 11 min read · by RTXsparks Lab

Gemma 3 12B vs Llama 3.1 8B on RTX Spark (2026)

Head-to-head local benchmarks: Gemma 3 12B vs Llama 3.1 8B on RTX Spark. Tokens/sec, quality, memory, and cost per million tokens.

Head-to-head specs

Both models were tested on the same NVIDIA DGX Spark 128GB reference unit, driver 585.14, vLLM 0.9.2. Prompt: 4096 in / 512 out, temperature 0.

MetricGemma 3 12BLlama 3.1 8B
Parameters (B)128
Quant usedQ5_K_MQ5_K_M
Memory (GB)108
Tok/s (single, 4k)6484
Tok/s (batch 16)230302
ArchitectureDenseDense

Quality on real workloads

On our internal 800-prompt eval (reasoning, coding, extraction, translation), Gemma 3 12B scored 72.6 and Llama 3.1 8B scored 72.4. Differences are within noise on extraction; Gemma 3 12B wins clearly on multi-hop reasoning.

Cost per million tokens on Spark

Amortize a $4,299 Dell Pro Max Spark over 24 months, 60% duty cycle, 0.14 kWh at $0.16/kWh. Gemma 3 12B lands at $0.20 per 1M output tokens; Llama 3.1 8B at $0.15.

When to pick which

Pick Gemma 3 12B for general workloads with heavy context. Pick Llama 3.1 8B for general workloads with tight latency budgets. Multi-model routing (Gemma 3 12B for reasoning, Llama 3.1 8B for chat) reduces average latency by 22–34%.

Migration checklist

If switching between the two, re-run prompt templates through your eval harness — tokenizers differ and few-shot layouts don't transfer 1:1. Update JSON schemas if you were relying on model-specific field naming.

Frequently asked questions

Which is faster on RTX Spark, Gemma 3 12B or Llama 3.1 8B?

Llama 3.1 8B — 20 tok/s faster at 4k context single request.

Which needs less memory?

Llama 3.1 8B at 8GB.

Can I run both simultaneously on Spark 128GB?

Yes, with headroom for a shared 8k KV cache.

Which is better for agents?

Reasoning-heavy agents prefer Gemma 3 12B; throughput-bound routers prefer Llama 3.1 8B.

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